Win32APIでCEFのオフスクリーンレンダリング　日本語入力

#include <windows.h>

#include <optional>
#include <iostream>
#include <include/cef_app.h>


#ifdef _DEBUG
#pragma comment(lib, R"(D:\libraries\CEF\cef_binary_138.0.15+gd0f1f64+chromium-138.0.7204.50_windows64\Debug\libcef.lib)")
#pragma comment(lib, R"(D:\libraries\CEF\MD\Debug\libcef_dll_wrapper.lib)")
#else
#pragma comment(lib, R"(D:\libraries\CEF\cef_binary_138.0.15+gd0f1f64+chromium-138.0.7204.50_windows64\Release\libcef.lib)")
#pragma comment(lib, R"(D:\libraries\CEF\MD\Release\libcef_dll_wrapper.lib)")
#endif

#include "MyCEFControl.hpp"

#include <Windows.h>
#include <windowsx.h>
#include <imm.h>

#pragma comment(lib, "imm32.lib")

void OnPaint(HWND hwnd, HDC hdc) {

    MyHandler* handler = (MyHandler*)GetWindowLongPtr(hwnd, GWLP_USERDATA);
    if (handler) {
        CefRefPtr<CefRenderHandler> baseRenderHandler = handler->GetRenderHandler();
        MyRenderHandler* renderHandler = static_cast<MyRenderHandler*>(baseRenderHandler.get());
        RGBAImage img = renderHandler->m_browserImage;
        if (img.buffer.size() > 0) {
            // ビットマップ情報の設定
            BITMAPINFO bmi;
            ZeroMemory(&bmi, sizeof(BITMAPINFO));
            bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
            bmi.bmiHeader.biWidth = img.width;
            bmi.bmiHeader.biHeight = -img.height; // 上下反転
            bmi.bmiHeader.biPlanes = 1;
            bmi.bmiHeader.biBitCount = 24; // RGB24ビット
            bmi.bmiHeader.biCompression = BI_RGB;
            // 画像データを描画
            SetDIBitsToDevice(
                hdc,
                0, 0,                  // 描画位置
                img.width, img.height, // 描画サイズ
                0, 0,                  // ソースの開始位置
                0, img.height,         // ソースの開始ラインとライン数
                img.buffer.data(),     // ピクセルデータ
                &bmi,
                DIB_RGB_COLORS         // カラーテーブルの使用方法
            );
        }
    }
}



void OnMouseMove(HWND hwnd, int x, int y) {
    MyHandler* handler = (MyHandler*)GetWindowLongPtr(hwnd, GWLP_USERDATA);
    if (handler) {
        CefMouseEvent mouse_event;
        mouse_event.x = x;
        mouse_event.y = y;
        mouse_event.modifiers = 0;
        handler->GetBrowser()->GetHost()->SendMouseMoveEvent(mouse_event, false);
        InvalidateRect(hwnd, NULL, FALSE);
    }
}



void OnLButtonDown(HWND hwnd, int x, int y) {
    MyHandler* handler = (MyHandler*)GetWindowLongPtr(hwnd, GWLP_USERDATA);
    if (handler) {
        CefMouseEvent mouse_event;
        mouse_event.x = x;
        mouse_event.y = y;
        mouse_event.modifiers = 0;
        handler->GetBrowser()->GetHost()->SendMouseClickEvent(mouse_event, cef_mouse_button_type_t::MBT_LEFT, false, 1);
        InvalidateRect(hwnd, NULL, FALSE);
    }
}



void OnLButtonUp(HWND hwnd, int x, int y) {
    MyHandler* handler = (MyHandler*)GetWindowLongPtr(hwnd, GWLP_USERDATA);
    if (handler) {
        CefMouseEvent mouse_event;
        mouse_event.x = x;
        mouse_event.y = y;
        mouse_event.modifiers = 0;
        handler->GetBrowser()->GetHost()->SendMouseClickEvent(mouse_event, cef_mouse_button_type_t::MBT_LEFT, true, 1);
        InvalidateRect(hwnd, NULL, FALSE);
    }
}



void OnClose(HWND hwnd) {
    MyHandler* handler = (MyHandler*)GetWindowLongPtr(hwnd, GWLP_USERDATA);
    if (handler) {
        handler->CloseAllBrowsers(true);
    }
}

std::optional<LRESULT>  WndProc_IME_Work(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
void SendKeyEventToBrowser(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);



LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) {
    MyHandler* handler = nullptr;
    LPCREATESTRUCT pcs;
    PAINTSTRUCT ps;
    HDC hdc;

    CefRefPtr<CefBrowser> browser;
    handler =
        reinterpret_cast<MyHandler*>(GetWindowLongPtr(hwnd, GWLP_USERDATA));
    if(handler)
        browser = handler->GetBrowser();


    SendKeyEventToBrowser(hwnd, msg, wp, lp);// キーボード入力のメッセージ処理

    auto imeret = WndProc_IME_Work(hwnd, msg, wp, lp);// IME関係のメッセージ処理
    if (imeret.has_value()) {
        return imeret.value();
    }

    switch (msg) {
    case WM_CLOSE:

        OnClose(hwnd);
        DestroyWindow(hwnd);

        return 0;
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        OnPaint(hwnd, hdc);
        EndPaint(hwnd, &ps);
        return 0;

    case WM_CREATE:
        pcs = reinterpret_cast<LPCREATESTRUCT>(lp);
        SetWindowLongPtr(hwnd, GWLP_USERDATA,
            reinterpret_cast<LONG_PTR>(pcs->lpCreateParams));

        return 0;
    case WM_DESTROY:
        //CefQuitMessageLoop();
        PostQuitMessage(0);
        return 0;

    case WM_MOUSEMOVE:
        OnMouseMove(hwnd, GET_X_LPARAM(lp), GET_Y_LPARAM(lp));
        return 0;
    case WM_LBUTTONDOWN:
        if (handler && browser)
            browser->GetHost()->SetFocus(true);
        OnLButtonDown(hwnd, GET_X_LPARAM(lp), GET_Y_LPARAM(lp));
        return 0;
    case WM_LBUTTONUP:
        OnLButtonUp(hwnd, GET_X_LPARAM(lp), GET_Y_LPARAM(lp));
        return 0;
    }

    return DefWindowProc(hwnd, msg, wp, lp);
}


///////////////////////////////////////////////
///////////////////////////////////////////////
///////////////////////////////////////////////
void HandleImeComposition(HWND hWnd,
    CefRefPtr<CefBrowser> browser,
    UINT msg, WPARAM wParam, LPARAM lParam);